Ecotin is a known serine protease inhibitor. The gene encoding this protein has been cloned, and the enzyme's properties characterized. The following is a brief summary of the known features of Ecotin:
Chung et al., 258 J. Biol. Chem. 11032, 1983, describe purification of a periplasmic protein, which they termed Ecotin, that is a potent inhibitor of pancreatic proteases, such as chymotrypsin, pancreatic elastase, rat mast cell chymase, and human serosal urokinase. The inhibitor does not inhibit human pulmonary tryptase, kallikrein, papain, pepsin, Staphylococcus aureus V8 protease, subtilisin, and thermolysin. Further, it does not inhibit any of the eight soluble endoproteases which are isolated from E. coli (including the proteases Do, Re, Mi, Fa, So, La, Ci, and Pi), nor the chymotrypsin-like (protease I) and trypsin-like (protease II) esterases in E. coli.
Palmer and St. John, 169 J. Bacteriology 1474, 1987, describe three membrane-associated serine proteases that are insensitive to inhibition by Ecotin, despite those proteolytic activities being present in E. coli.
McGrath et al., 266 J. Biol. Chem. 6620, 1991, describe Ecotin as an unusual serine protease inhibitor since it is able to inhibit chymotrypsin, trypsin and elastase.
McGrath et al., 222 J. Molecular Biol. 139, 1991, describes expression of Ecotin in the E. coli periplasm, using the endogenous signal peptide and the heterologous tac promoter.
Lee et al., 287 FEBS Letters 53, 1991, describe a nucleotide sequence of 876 bases in the E. coli chromosome that encodes Ecotin. They proposed that the coding sequence for Ecotin is 486 nucleotides long, and encodes a protein consisting of 162 amino acids.